(a) Field of the Invention
The present invention relates to a reverse offset printing method, and more particularly to a reverse offset printing method in a partial off type capable of accurately transferring a pattern to a cliche to achieve more precise minute printing by separately performing removal for each shear region of a functional ink even though the pattern is minute.
(b) Description of the Related Art
In general, a cliche (C, see FIG. 1) performs patterning while coming into contact with a blanket B coated with a functional ink and offs (removes) an unnecessary pattern other than a desired shape.
Hereinafter, a reverse offset electronic printing apparatus 10 will be described as an example, as illustrated in FIG. 1.
The reverse offset electronic printing apparatus 10 includes a blanket B coated with a functional ink I and a cliche C coming into contact with the blanket B to remove an unnecessary pattern.
That is, as illustrated in FIG. 1, the blanket B coated with the functional ink I is first prepared.
The functional ink I may be coated on the blanket B through widely known methods such as spin coating, slit coating and the like.
The above-mentioned blanket B coated with the functional ink I is brought into contact with the cliche C including a groove portion CV.
In this case, the functional ink coming into contact with the groove portion CV remains on the blanket B, and the functional ink coming into contact with a contact surface CA of the cliche C is transferred to the cliche C.
That is, a part desired to be patterned remains on the blanket B and is transferred to a substrate S, and then printing is performed.
Meanwhile, in a recently spotlighted electronic printing field, a width of the pattern is equal to or smaller than scores of um in many cases.
Accordingly, as illustrated in FIG. 2, a width L of the groove portion CV of the cliche C is also equal to or smaller than scores of um.
However, as described above, as the width of the pattern becomes more minute, a size of the pattern remaining on the blanket B becomes very small in comparison with a size of the functional ink transferred to the cliche C from the blanket B.
In this case, the functional ink which should remain on the blanket B and then be finally transferred to the substrate does not remain on the blanket B and is transferred to the cliche C sometimes.
The above case may be generated by a phenomenon in which since adhesive force between the blanket B and the functional ink is weaker than shear force of the function ink as illustrated in FIG. 3, a connection portion II (hereinafter, referred to as a shear region) between the functional ink which should remain on the blanket B and the functional ink transferred to the cliche C cannot be cut when the blanket B and the cliche C are separated from each other.
In this case, the functional ink which should remain on the blanket B is taken to the cliche C, and thus accurate printing is not possible.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.